Topic: Adjective (বিশেষণ),

Best Answer Explained in Below-:

In the sentence "The college teacher is popular among his students," the term "popular" serves as an adjective. An adjective is a word that describes or modifies a noun, providing more information about it. In this case, "popular" describes the noun "teacher," indicating the level of regard or admiration the students have for him.

To better understand this, we can analyze the structure of the sentence. The subject is "the college teacher," and the verb is "is." The word "popular" follows the verb and is linked to the subject, functioning to attribute a quality to the teacher. Adjectives often answer questions such as "What kind?" or "How many?" Here, "What kind of teacher?" the answer is "a popular one."

In contrast, nouns denote people, places, or things; verbs express actions or states of being; and adverbs modify verbs, adjectives, or other adverbs. Since "popular" does not fit into these categories but instead describes the teacher, it clearly identifies itself as an adjective. Thus, option B is the correct answer.